We're still a week away, so these extended forecasts are far from set in stone. On the contrary, we all know that they sometimes change within the same day, nevermind in an intervening week. But it's initial information at least.

Weather.com, Weather Underground, and Accuweather are all predicting a mostly sunny Wednesday and Thursday for Indianapolis, some clouds, highs in the 80s, lows in the mid 60s. The first two predict "PM Thunderstorms" on Friday, and Accuweather simply says "a thunderstorm around late". Late what? Well... ¯\_(ツ)_/¯; they don't say.

I like using the NOAA forecasts the best, but they don't extend their predictions out that far.

If these are even generally indicative, it says there's a good chance of rain at some point later on Friday. There are predictions that go out further, but those are probably too prone to change. At any rate, bringing an umbrella or otherwise planning for some rain at some point seems to be a good idea.

In the midwest, you'll typically get thunderstorms around sunset due to the convective heat buildup (heat radiating from the ground into cooler air), and if there is a lot of moisture in the air, you'll get towering Cumulonimbus clouds (anvil shaped thunderhead clouds). That's why mid afternoon, it can be clear blue sky. Then around 6-7pm, you'll see huge, billowing anvil shaped clouds throwing out lightning, thunder, rain, maybe hail... and of course, possible tornadoes, but that's typically from weather fronts and the complex interaction of high/low pressure systems and etc. etc.

I'm bringing an umbrella because I'm not connected to the convention center via hamster tube.

It isn't totally random as you can generally get an idea of what pockets of air around and will have some liklihood of moving over the area. Especially since in Indiana, you often are getting the weather fronts that were in the plains states like Nebraska and the Dakotas a few days earlier. So if they are somewhat reasonably sure what kind of fronts to expect in South Dakota 2 or 3 days from now, there is at least a reasonable chance to expect that frontal boundary to continue east and reach Indiana about 2 days later. Anything more than that isn't worthless. It's just computer models and educated guesswork about what high and low pressure centers will be doing once those fronts go through, which gives you a pretty good idea what to expect for a few days after that 4-5 day forecast.

If a high pressure center is going to follow a warm air frontal boundary, you can probably be reasonably assured of a few days of nice weather with little to no chance of precipitation. If Indiana currently has a High pressure that is starting to move away and you are seeing a low pressure that has a chance to move in, then you start looking at higher winds, and a greater liklihood of rain.

It isn't trash, it just isn't a perfect science at 7-8 days out based on the complexities of the air patterns for the entire globe. (Not to mention if you get a tropical storm developing in the western Atlantic or Gulf, that tends to draw most of the moisture that would cause rain in and around Indiana.

Well, to forestall a debate, yeah, it's all chaotic - and I mean in the scientific sense of dynamic, nonlinear systems that are sensitive to initial inputs. And that beyond a certain point we have an idea of what the probability is that weather events occur, but it's hardly certain, and that certainty deteriorates the farther out you get. So it's not dependable at all in a human sense, but at the same time it's not out of thin air.

It's not a debate, it's just the nature of "prediction." Obviously we can say if things are one way now, they may somehow in some way look like /this/ in 7 days. But it could also look like that. That there. And this too.

It's random 7-8 days out - accuracy in predictions fluctuates wildly. It's nearly a coin toss. Weather accuracy charts look like large zig zags with very dramatic shifts. Those shifts increase sharply after 3 days and dramatically after 6 or 7 days.

There are so many variables, possibilities, changes, and outside influences affecting area specific forecasts that to say with any amount of certainty you know it will rain or shine in 7-8 days is silly.

 lordnlkon wrote:God that sounds amazing. Can’t wait to get out of this 110 degree weather in Texas.

And out the 110 and smoke (I'm near the Ferguson fire by Yosemite) in California. Waking up every morning to a thick layer of smoke and ash is getting old (okay, not "getting"; "got", about a day after the fire started).

 lordnlkon wrote:God that sounds amazing. Can’t wait to get out of this 110 degree weather in Texas.

I am with you.I am going to have bring my medium weight jacket and possibly long sleeves since highs in the 80s, lows in the mid 60s is definitely cold.

I am amused at the temperature variations across our huge continent; I've lived in northern Michigan where a temperature in the mid 50s was so blisteringly hot that no one does anything but try to stay in the shade all day. Personally I can't conceive of wearing a jacket above 55 F or so...60 F is good swimming weather. "Cold" begins when there is a minus sign in front of the temperature in F. My wife complains when I set the hotel room to 65 but even at that temperature it's too hot for sheets while sleeping.

 ryric wrote:I am amused at the temperature variations across our huge continent; I've lived in northern Michigan where a temperature in the mid 50s was so blisteringly hot that no one does anything but try to stay in the shade all day. Personally I can't conceive of wearing a jacket above 55 F or so...60 F is good swimming weather. "Cold" begins when there is a minus sign in front of the temperature in F. My wife complains when I set the hotel room to 65 but even at that temperature it's too hot for sheets while sleeping.

Over half the people I know are like that, and are comfy wearing single layers of clothing in the 40s. But my genetic heritage (eastern Pacific) is for heat, and man I suffer in the winter :( . In the lower 60s I am definitely cold, and I even break out the sweaters in the 50s. My parents wore those well into the mid-60's. The other day my car's external temp reading said "88 F", and I didn't even have the air conditioning on.

As weird as the temperature variations are, I'm every bit as amused by the comfort variations of us humans. At work, I could literally be in my jacket shivering while a college complains about feeling too hot. This has happened before. :D

I prefer cooler temps. 55°f-65°f is about perfect shorts and t-shirt weather. Anything more is too hot. It's not cold to me until it's >20°f. It's been stupid hot around here (Portland, OR). 90+°f for over 10 days. It's usually 82°f this time of year. And the forecast says at least another five days of 90°f+ days. No one around here has Air Conditioning, because it doesn't get hot enough for it until late August for maybe a couple days. Climate change is real folks. And we are seeing it now!

That being said, I like walking outside at GenCon, rain or shine. If you have the right hotel, you could check in Wednesday night, and stay indoors using the Hamster Tubes until you check out on Monday. Yeah, it's nice to have AC, but to say inside all the time... bleh. I lived in Oklahoma City for eight years, and from May until September, you stayed inside as much as possible, and it sucked. I swore to myself I'd never live in a place again that requires Air Conditioning and measures the temperature with a "Heat Index" or "Wet Bulb Globe Temperature". Frak that! Oh, and after 23 years in the US Air Force, I've spent far too much time in Teh -Stans and the Middle East in general. I've been in 130° heat, and no, it's not fun.

Our group to Gen Con is myself, my wife, and our friend. My wife losing in this as she prefers to be warm, while our friend and myself prefer cool. We will be at the Hyatt and will not be outside of the tubes while the sun is up. Won't happen. I always say its easier to stay warm than stay cool. A perfect day for me is in the 50s with clouds. Keep that sun and heat away. lol

The NOAA has finally put up some detailed predictions for Indianapolis. For Wednesday they say:

WednesdayA 30 percent chance of showers and thunderstorms, mainly after 3pm. Partly sunny, with a high near 81.
Wednesday NightA 30 percent chance of showers and thunderstorms before 9pm. Partly cloudy, with a low around 64.

They have predictions out to Sunday, but again, forecasts that far out are not terribly reliable. Wunderground, Accuweather and Weather.com are now both calling Wednesday the rain day, with Thursday and Friday being the clear ones, but the same caveat applies. A lot can change in a single day, let alone 4 or 5. Wednesday is when we can have confidence in the Thursday and Friday forecasts.